search for: v4l2_flag_memory_non_consist

...a/Documentation/userspace-api/media/v4l/buffer.rst > +++ b/Documentation/userspace-api/media/v4l/buffer.rst > @@ -701,23 +701,6 @@ Memory Consistency Flags > :stub-columns: 0 > :widths: 3 1 4 > > - * .. _`V4L2-FLAG-MEMORY-NON-CONSISTENT`: > - > - - ``V4L2_FLAG_MEMORY_NON_CONSISTENT`` > - - 0x00000001 > - - A buffer is allocated either in consistent (it will be automatically > - coherent between the CPU and the bus) or non-consistent memory. The > - latter can provide performance gains, for instance the CPU cache > - sync/flush ope...

...nimplemented except on PARISC and some MIPS configs, and about to be >> removed. > > It is implemented by the generic DMA mapping layer [1], which is used > by a number of architectures including ARM64 and supposed to be used > by new architectures going forward. AFAICS all that V4L2_FLAG_MEMORY_NON_CONSISTENT does is end up controling whether DMA_ATTR_NON_CONSISTENT is added to vb2_queue::dma_attrs. Please can you point to where DMA_ATTR_NON_CONSISTENT does anything at all on arm64? Also, I posit that videobuf2 is not actually relying on DMA_ATTR_NON_CONSISTENT anyway, since it's clearly not...

...752aaf414a7..2044ed13cd9d7d 100644 --- a/Documentation/userspace-api/media/v4l/buffer.rst +++ b/Documentation/userspace-api/media/v4l/buffer.rst @@ -701,23 +701,6 @@ Memory Consistency Flags :stub-columns: 0 :widths: 3 1 4 - * .. _`V4L2-FLAG-MEMORY-NON-CONSISTENT`: - - - ``V4L2_FLAG_MEMORY_NON_CONSISTENT`` - - 0x00000001 - - A buffer is allocated either in consistent (it will be automatically - coherent between the CPU and the bus) or non-consistent memory. The - latter can provide performance gains, for instance the CPU cache - sync/flush operations can be avoided if the buffer is acc...

...752aaf414a7..2044ed13cd9d7d 100644 --- a/Documentation/userspace-api/media/v4l/buffer.rst +++ b/Documentation/userspace-api/media/v4l/buffer.rst @@ -701,23 +701,6 @@ Memory Consistency Flags :stub-columns: 0 :widths: 3 1 4 - * .. _`V4L2-FLAG-MEMORY-NON-CONSISTENT`: - - - ``V4L2_FLAG_MEMORY_NON_CONSISTENT`` - - 0x00000001 - - A buffer is allocated either in consistent (it will be automatically - coherent between the CPU and the bus) or non-consistent memory. The - latter can provide performance gains, for instance the CPU cache - sync/flush operations can be avoided if the buffer is acc...

...some MIPS configs, and about to be > >> removed. > > > > It is implemented by the generic DMA mapping layer [1], which is used > > by a number of architectures including ARM64 and supposed to be used > > by new architectures going forward. > > AFAICS all that V4L2_FLAG_MEMORY_NON_CONSISTENT does is end up > controling whether DMA_ATTR_NON_CONSISTENT is added to vb2_queue::dma_attrs. > > Please can you point to where DMA_ATTR_NON_CONSISTENT does anything at > all on arm64? > With the default config it doesn't, but with CONFIG_DMA_NONCOHERENT_CACHE_SYNC enabled it...

...about to be >>>> removed. >>> >>> It is implemented by the generic DMA mapping layer [1], which is used >>> by a number of architectures including ARM64 and supposed to be used >>> by new architectures going forward. >> >> AFAICS all that V4L2_FLAG_MEMORY_NON_CONSISTENT does is end up >> controling whether DMA_ATTR_NON_CONSISTENT is added to vb2_queue::dma_attrs. >> >> Please can you point to where DMA_ATTR_NON_CONSISTENT does anything at >> all on arm64? >> > > With the default config it doesn't, but with > CONFIG_DM...

Hi all, this series replaced the DMA_ATTR_NON_CONSISTENT flag to dma_alloc_attrs with a separate new dma_alloc_pages API, which is available on all platforms. In addition to cleaning up the convoluted code path, this ensures that other drivers that have asked for better support for non-coherent DMA to pages with incurring bounce buffering over can finally be properly supported. I'm still a

...removed. > >>> > >>> It is implemented by the generic DMA mapping layer [1], which is used > >>> by a number of architectures including ARM64 and supposed to be used > >>> by new architectures going forward. > >> > >> AFAICS all that V4L2_FLAG_MEMORY_NON_CONSISTENT does is end up > >> controling whether DMA_ATTR_NON_CONSISTENT is added to vb2_queue::dma_attrs. > >> > >> Please can you point to where DMA_ATTR_NON_CONSISTENT does anything at > >> all on arm64? > >> > > > > With the default config it do...

Hi all, this series replaced the DMA_ATTR_NON_CONSISTENT flag to dma_alloc_attrs with a separate new dma_alloc_pages API, which is available on all platforms. In addition to cleaning up the convoluted code path, this ensures that other drivers that have asked for better support for non-coherent DMA to pages with incurring bounce buffering over can finally be properly supported. I'm still a

Hi all, this series replaced the DMA_ATTR_NON_CONSISTENT flag to dma_alloc_attrs with a separate new dma_alloc_pages API, which is available on all platforms. In addition to cleaning up the convoluted code path, this ensures that other drivers that have asked for better support for non-coherent DMA to pages with incurring bounce buffering over can finally be properly supported. As a follow up I